"Creative Illustration" is an amazing book. It is extremely useful, advice given in the book is exceptional. Most things discussed and showcased in this book I have never seen in any other art books (contemporary or vintage). Unique. Unbelievably good.
This book made me a better artist, and I feel like now I understand everything with so much more depth.
Loomis also gives a little insight in master Pyle's methods, compositions and advice for success in the industry that is still valid today.
Best investment of a hundred dollars I've ever made. A definite must have for a professional, a gem for the serious student of illustration.

(Note: This book is not for beginners. It's for people who are serious about the business. If you're just starting out, just get one of those "how to draw (insert whatever) books" and come and get this book in a couple of years.)